Celestial hemisphere:  Northern  ·  Constellation: Ophiuchus (Oph)  ·  Contains:  NGC 6384
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NGC 6384 |  A Barred Spiral Lurking in a Field of Stars, Kevin Morefield
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NGC 6384 | A Barred Spiral Lurking in a Field of Stars

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NGC 6384 |  A Barred Spiral Lurking in a Field of Stars, Kevin Morefield
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NGC 6384 | A Barred Spiral Lurking in a Field of Stars

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Description

I counted 47 images on AB of NGC 6384, which is surprisingly few for a northern hemisphere NCG Galaxy 6-7 arc-minutes in size.  I suspect the reason it is so seldom a target has to do with the rich Ophiuchus star field in which it lies and its relatively dim surface brightness.  Regarding the size, TheSkyLive lists it at 2.5'x1.1' and CCDNav lists it at 6.2' on its long side.  I measured it at 7'x5.3' at the furthest extent I captured.

I struggled a bit with how to crop.  The star field is a feature of the image and I thought it would help avoid a smack-dab-in-the-center framing of the galaxy.  But the star field is relatively centered unless I used nearly the entire full-frame FOV.  That left the galaxy detail too small so here another nearly centered galaxy!

Linear processing was done in PI and the RGB masters were combined with Luminance to produce a Super-Luminance.  ArcSinh was used for RGB stretching and Masked stretch used on the Super-Luminance.  Each received a second stretch with Histogram Transformation to add a little contrast.  

Non-linear processing was done in Photoshop.  I used Russell Croman's new StarXTerminator to produce star masks.  This is faster than Starnet++ and since I only use these to make star masks I'm not too concerned about which produces fewer artifacts.  The process is to run the routine on a copied layer, change the layer type to "difference" and finally do a Highlights selection down to maybe 8/255 counts.  From there I expand the selection a bit, feather and I have my nearly perfect star mask.

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    NGC 6384 |  A Barred Spiral Lurking in a Field of Stars, Kevin Morefield
    Original
  • Final
    NGC 6384 |  A Barred Spiral Lurking in a Field of Stars, Kevin Morefield
    C

C

Description: Rotate and Crop

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NGC 6384 |  A Barred Spiral Lurking in a Field of Stars, Kevin Morefield

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